In metal spinning, a blank in the form of a sheet metal disk or a preform is rotated and formed into the desired, rotationally symmetric part by approaching and pressing a spinning tool against it.
A survey of known spinning processes is given in Blech-Rohre-Profile (1981) 11, pages 514 to 517.
In the known spinning processes, the blank is clamped centrically in a spinning chuck, the outside contour of which corresponds to the inside contour of the part to be formed. The spinning tool in the form of a spinning roller however follows the outside contour of the part to be formed in such a way that the blank can be formed between the spinning roller and the spinning chuck. Furthermore, it is known to use an internal spinning chuck with an inside contour that corresponds to the outside of the part to be formed.
In modern spinning devices, the spinning roller is motion-controlled via copying templates or via a numerical control. Although materials which are difficult to deform have already been spun by applying known spinning processes, the known processes are limited as to the forming of materials of increased strength into shapes with varying wall thickness and/or high demands on dimensional accuracy. When spinning materials of increased strength, springback is likely to occur. Thus dimensionally correct forming of such materials in a spinning chuck is very difficult.
Although spinning chucks can be manufactured relatively easily, the production costs are noticeably reflected in the cost of the formed part when only small quantities of parts are to be formed. If the material is spun prior to a strength-increasing heat treatment in order to improve its deformability during the subsequent heat treatment, especially with parts of varying wall thickness, dimensional deviations and especially inhomogeneities in the transition area between areas of different wall thickness may occur, which cannot be accepted for precision parts such as bottoms of fuel tanks for the aerospace industry.